WASHINGTON — The drive to end the bulk collection of phone records by the National Security Agency is gaining strength, as Senate Democrats said Sunday that Congress will change the law to ban the practice if President Obama does not do it first.

“It’s time to have real reform, not a veneer of reform,” said Sen. Mark Udall (D-Colo.), a longtime critic of the NSA. “We have got to rebuild the American people’s trust in our intelligence community so we can be safe,” he said on ABC’s "This Week." “But we don’t do that by bulk data collection that violates the privacy of Americans. That’s unconstitutional, and has shown to not be effective.”

Last week, a federal judge said the routine collection of the dialing records is probably unconstitutional, and a panel appointed by President Obama recommended a major change.

“We believe the government shouldn’t hold this data any longer,” Michael Morrell, a former acting director of the CIA and a panel member, said on CBS’ "Face the Nation."

He said the phone records could be held by the phone companies or by another private group. Then, the government would “need a court order every time they wanted to query that data,” he said.

Despite the need for reforms, Morrell said the original purpose of the program still makes sense. He said it is crucial the NSA and the FBI can move quickly if there is reason to believe that a “terrorist overseas is talking to someone in the United States.”

But the government does not need to collect and store all of these dialing records, he said, so long as they are held in private hands.

The USA Patriot Act authorized the government to collect phone records and other data that would be “relevant to an authorized investigation.”

To the surprise of many in Congress, the NSA went to a secret court and won the authority to collect all the dialing records of phone calls in the United States because they might prove useful in a future investigation.

The Leahy-Sensenbrenner bill would change the law and forbid this bulk collection of phone data. “Momentum is building for real reform,” Leahy said Sunday.